Randall A. Hawkins

Learn More
To evaluate the feasibility of quantitatively assessing regional skeletal fluoride uptake in humans in focal and generalized bone disease, we investigated the skeletal kinetics of [18F]fluoride ion with dynamic PET imaging. Dynamic image sets were acquired over a 60-min interval in a multiplane PET device, and input functions (plasma 18F time-activity(More)
UNLABELLED Partial-volume errors (PVEs) in PET can cause incorrect estimation of radiopharmaceutical uptake in small tumors. An iterative postreconstruction method was evaluated that corrects for PVEs without a priori knowledge of tumor size or background. METHODS Volumes of interest (VOIs) were drawn on uncorrected PET images. PVE-corrected images were(More)
OBJECTIVE Our objective was to evaluate if whole-body PET with FDG is able to detect bone marrow involvement in patients with multiple myeloma and to assess its appearance and distribution pattern. MATERIALS AND METHODS Seventeen whole-body FDG PET scans were performed in 13 patients with multiple myeloma. Four patients were referred for evaluation of(More)
A quantitative preoperative technique using thallium-201 single-photon emission computerized tomography is described which predicts whether specific gliomas are of high- or low-grade malignancy. An index, based on the ratio of thallium uptake in the tumor versus the homologous contralateral brain, was calculated and compared with tumor histology. The index(More)
UNLABELLED The purpose of our study was to determine the effect of tumor-targeted radiation in neuroblastoma by correlating administered (131)I-metaiodobenzylguanidine (MIBG) activity to tumor and whole-body dosimetry, tumor volume change, overall response, and hematologic toxicity. METHODS Eligible patients had MIBG-positive lesions and tumor-free,(More)
Two types of image similarity measures, the sum of absolute differences (SAD) and the stochastic sign change (SSC), were compared for three-dimensional registration of images from PET. To test the accuracy of both registration methods, 30 FDG brain studies, 40 13N-ammonia cardiac studies and 20 FDG liver tumor studies (where each image set contained 15(More)
We evaluated the bone metabolic activity in patients with renal osteodystrophy using positron emission tomography and [18F]fluoride ion. Eight patients had secondary hyperparathyroidism (HPT), and three had low-turnover bone disease. Eleven normal subjects were also studied, and three of the eight HPT patients were reevaluated after therapy. A rate constant(More)
PURPOSE To evaluate the safety and efficacy of high-dose [(131)I]metaiodobenzylguanidine ([(131)I]MIBG) in the treatment of malignant pheochromocytoma (PHEO) and paraganglioma (PGL). METHODS Fifty patients with metastatic PHEO or PGL, age 10 to 64 years, were treated with [(131)I]MIBG doses ranging from 492 to 1,160 mCi (median, 12 mCi/kg). Cumulative(More)
The objective of this retrospective study was to compare the diagnostic value of 2-[18F]fluoro-2-deoxy-d-glucose positron emission tomography (18F-FDG PET)/CT versus 18F-FDG PET and CT alone for staging and restaging of pediatric solid tumors. Forty-three children and adolescents (19 females and 24 males; mean age, 15.2 years; age range, 6–20 years) with(More)
Recent studies suggest that thallium-201 (201Tl) planar scans of brain tumors more accurately reflect viable tumor burden than CT, MRI, or radionuclide studies with other single-photon emitting compounds. We have previously reported the utility of 201Tl SPECT index in distinguishing low- from high-grade gliomas elsewhere. Here we describe the technical(More)